In general, vehicles offer convenience of mobility and time efficiency for persons, but require care during use because of causing serious damage to surrounding persons in addition to a driver due to carelessness of the driver. Particularly, in recent years, intelligent and enhanced vehicles are gradually increased by technological convergence of vehicles and ICT (Information & Communication Technology). Thus, safe driving assistance systems provided in the vehicles serve to recognize dangerous situations and inform a driver of the recognized situations. As disclosed in Korean Patent Publication No. 10-0282903 (Dec. 2, 2000), a conventional safe driving assistance system for vehicles mainly recognizes dangerous situations by collecting information through external sensors (radar, cameras, etc.) to determine whether or not the dangerous situations (lane departures, expected collisions, etc.) are present.